max boost on t2
Turbo Mini Forums

i was just wondering what's the highest boost a standard t2 could reliably handle, anyone know?
cheers
DAN :)

It's not really down to how much boost the Turbo can produce, it's more how much "effective" boost the Turbo can produce.
There will become a point where all you will be doing is heating the charge more, rather than producing a power increase, even a big intercooler may not be able to neutralise this.
For example, a friend ran 25psi on a T2 last year. When raising the boost there was a noticable increase in power between 10-15psi, the difference between 15-20 psi was not as good and 20-25 was only slightly better. I suspect the efficiency of the Turbo was dropping off rapidly at aound 20psi.
Remember the T2's are only small units.

Phil.

WWW.TURBO-MINI.COM

More boost also kills these turbos..

A std t2 lasts about 50k miles on a R5GTT but that drops to 20k if you push the turbo to about stage one.

Alex

AlexF

ok cheers
DAN :)

i know a friend of mine destroyed a r5 t2 running ajustable boost up to 30 psi (*a large proportion of the time!), lasted about 10000 miles in his hands, (tho had been on the car a long time)

And on the 7th day........... God created turbochargers!

Well.......you can all shoot at me if you like.....but heres my view......

Isn't the whole thing about so called "Maximum Boost" something that really isn't that relevant when it comes to actually setting up an engine? It seems to me that the whole "Max Boost" thing is better left to those people that feel the need to boast in the pub or in "Lax Flower" Magazine, about their mega Renault 5 or Escort or whatever.

Personally I see the approach to building and tuning a reliable and powerful engine is to firstly build a strong base on which to start. Then to run a sensible amount of boost pressure in order to realise the potential of that solid base.

As someone else said, boost increases have a proportionally less marked effect as you increase the pressure, mainly due to the laws of thermodynamics, and the limitations of installing an efficient intercooler in the limited space we have to play with.
The other side to this, and in effect as with everything to do with tuning cars, is the perenial idea, that if some more is good, loads more is better.......and I don't count myself in the past out of that one, yes I did once fit a 276 cam to a 998 engine, and yes it was virtually undriveable, and so we live and learn.

i'm not going to shoot you, we are all entitled to our views and most of the time the views are relevant, i agree that the best thing is to build the engine then do all the details, i was just interested to know.
cheers
DAN :)

p.s, max power sucks

max power dude !!!!



DAN

makes me smile every time i see that!!

And on the 7th day........... God created turbochargers!

10000 miles, that would last me around 10 years! I'm happy with that!

Team Racing

ah, 500 years for me

Max recommeded boost pressure for a standard spec R5 unit is 10psi to give good service life. It's mainly down to the specification of the thrust bearings used in the turbo. Standard R5 uses a 270 degree metal bearing, similar kind of material to your engine bearings. The lateral loads are also supported on metal bearing. The shaft is meant to float in a film of oil, so in theory it dosen't touch the bearing. The more boost you run the more thrust that is applied to the thrust bearing. This extra pressure pushes out oil and if sufficient will result in rubbing and premature wear. The next step is to use a 360 degree bearing as this has a greater surface area and can so take greater load without failure. Think i have seen these in ceramic materials as wellThese are ok for 15-18psi. For really serious use you are talking about using ball bearings (can be metal or ceramic). These are much happier with the higher loading. Trade of is they are expensive as you need a pretty good spec bearing to at over 100,000 rpm in what isn't an ideal enviroment.